Hand transmission of viruses is recognized as an important factor in the occurrence of respiratory and enteric diseases. Transfer of virus can occur to and from hands, as well as between hands and fomites (a fomite is an object or substance capable of carrying infectious organisms). At high concentrations, alcohol is rapidly bactericidal against gram positive and gram negative vegetative bacteria. The U.S. Food and Drug Administration (“FDA”) has determined that alcohol at 60-95% concentrations in aqueous solutions is safe and effective as a germicide and therefore acceptable.
Certain enveloped viruses are susceptible to high concentrations of alcohol as well. However, low concentrations of alcohol are not considered to be effective in inactivating viruses. Moreover, alcohol, even at high concentrations, has poor activity against nonenveloped viruses.
Norovirus, a non enveloped virus, is the most common cause of viral gastroenteritis. Surveillance study determined that around 90% of all non-bacterial outbreaks in Europe could be attributed to norovirus (Lopman et al., 2003). This resilient virus can be spread by person to person contact, via aerosols, through contaminated food and water as well as via environmental surfaces. It is capable of causing sporadic cases as well as large outbreaks which typically occur within institutionalized settings such as hospitals, schools or cruise ships. Feline calicivirus is currently the most widely used surrogate virus as it has a similar genome organization, capsid architecture and biochemical properties as that of norovirus.
Doultree et al., “Inactivation of feline calicivirus, a Norwalk virus surrogate,” J. Hosp. Infec. 1999, 41:51-57, reported that quaternary ammonium product, detergent and ethanol failed to inactivate the virus.
Duizer et al., “Inactivation of Caliciviruses,” Applied and Environmental Microbiology, August 2004, p, 4538-4543, reported that inactivation of feline calicivirus, a widely studied norovirus surrogate, by 70% w/w ethanol in room temperature was inefficient with less than log10 2 reduction after 8 minutes and log10 3 reduction after 30 minutes.
Hand sanitizers are the most popular amongst sanitizers. The active ingredient in sanitizers is in most cases ethanol, isopropanol, or n-propanol. A variety of preparations are available, including gels, foams and liquid solutions. Hand sanitizers containing alcohol are more effective at killing germs than soaps. On the other hand, the alcohol-based sanitizers, while having demonstrated good antimicrobial activity, have poor antiviral activity against nonenveloped viruses.
In order to achieve antiviral activity non-GRAS ingredients (i.e., ingredients that are not “Generally Recognized as Safe” by US FDA standards) have been added to sanitizing compositions containing alcohol at high concentrations, e.g., hydrogen peroxide, sulfonates, thiocyanate, formaldehyde, organic acids in high concentration, cationic surfactants, organic amines, cationic polymers or combinations thereof.
FDA (ISSA Guide to the Regulations of Antibacterial Hand Soaps) has determined that alcohol 60-95% in an aqueous solution is safe and effective as a germicide and therefore acceptable. In ethanol based sanitizing compositions on the market, ethanol needs to be at a high concentration (60-95%). These products have many disadvantages, like drying and irritating of the skin, especially on repeated use, by removing the protective layer of the skin. In order to overcome the drawbacks of dryness and irritation, compositions were previously formulated by using humectants, silicones, detackifiers (U.S. Pat. No. 6,423,339 to Procter & Gamble) and/or polymers as excipients in the sanitizing compositions.
However, there remains an unmet need for highly effective sanitizing compositions exhibiting strong antiviral activity, preferably comprising safe GRAS ingredients exhibiting minimal side-effects. The present invention provides such compositions.